Picked up a '09 D40 auto a couple of months back, had an issue with blowing smoke initially however some local mechanic switched the dpf system off in the ecu which appears to have solved the problem. I'm told the previous owner had removed the entire dpf system and the cat, and an affordable replacement dpf system could not be found. Aside from being a little beat up, I'm happy with the truck and it's doing what I bought it to do! Happy to have found this forum as I might try solving problems myself in future, though I'm clearly no mechanic haha.